1. Field of the Invention
The present invention relates to a pharmaceutical composition containing urokinase having improved characteristics for intestinal absorption.
More particularly, it is concerned with a pharmaceutical composition containing urokinase improved in intestinal absorbability comprising urokinase and a physiological absorption enhancer.
Urokinase is a fibrinolytic and thrombolytic enzyme. Clinically, it is useful as a thrombolytic agent for a variety of thrombosis such as cerebrovascular obstruction, myocardial infarct and pulmonary embolism. It is also used in combination with antitumor agents.
2. Prior Art
The route of administration of drugs is classified into divisions such as injectable, oral and topical ones. Except for special cases, oral administration is more useful than parenteral in view of the troubles of patient, physician and other persons concerned as well as patients suffering so far as the same result is produced.
When orally administered, urokinase is decomposed and inactivated in the stomach by the actions of such substances as proteases and a gastric acid. Moreover, it is poorly absorbed from the intestinal tract. Heretofore, it has been administered by intravenous injection or by intravenous infusion. Although urokinase can be administered by these routes of administration without decomposition and inactivation, they are unsatisfactory in that each administration has to be exercised by a physician and the patient suffers pain.
In addition, as urokinase has a half life in blood as short as approximately 15 min., maintaining urokinase in blood at a given level is difficult and the effect of the drug is not durable.